A Quantitative Measurement and Validation of Granularity in Service Oriented Architecture

The prominent principle of designing service in Service Oriented Architecture is service granularity. The granularity is a crucial design decision. The service should be neither too coarse nor too fine grained. Therefore it should be evaluated at the design phase itself to measure its level of appropriateness. This paper proposes a suite of metrics for measuring service granularity quantitatively. Although many metrics have already been defined to measure service granularity, their attention in measuring service interface granularity is very less which affects the other design principles coupling and reusability. This paper proposes a metric for measuring granularity of a service by considering its composite level, functional richness and its interface granularity. The paper also validates the proposed metrics theoretically and a case study is performed to analyze the proposed metrics.